Electromagnetic Spectrum

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Electromagnetic Spectrum

• Light, et al.

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Light

• Travels as a transverse wave
• Travels at 300,000 km/second in vacuum slower in
  other media

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White light is a mixture of the visible colors
Visible range 400 nanometers (violet)
to 700 nanometers (red)
(1 nanometer (nm) 109 meters)
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Infrared light is real!
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With light, wavelength determines color
microwaves
Most colors are invisible to our eyes!
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Light also behaves like particles (photons)
A 100-watt bulb emits 3 x 1020 photons per second
The energy per photon depends on the wavelength
of the light shorter wavelength (faster
wiggling) implies higher energy per photon. So
a blue photon packs more punch than a red photon
an ultraviolet photon can break molecules apart,
and an x-ray photon is still more energetic.
ultraviolet
blue
red
infrared
highest energy
lowest energy
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To summarize the relationships

• Short wavelengths of light
• Have high frequencies
• Are high energy
• Light, radio, X-rays and heat are all types of
  the same thing electromagnetic radiation, or EM
  radiation for short.

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Graphs of thermal spectrum
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Orion star colors